Des Moines River Basin Master Regulation Manual Update

The current Des Moines River Water Control Plans were approved in 1992 (Lake Red Rock) and 2001 (Saylorville Lake). The Water Control Plans consist of operational parameters defining how, and when, water is stored and released. These include a schedule of releases, conservation pool levels to be maintained during non-flood or drought conditions and downstream water level constraints.

The following key issues inform the primary purpose and need of the Des Moines River Basin Master Reservoir Regulation Manual update:

1. The Des Moines River has experienced a significant increase in the magnitude and frequency of flooding.

3. Deviations from the approved water control plans, approved and conducted in recent years, demonstrate the need to permanently update the water control plans for each of these reservoirs.

The Des Moines River Basin has experienced significant land use changes. These changes influence runoff rates into tributaries of, and the main stem Des Moines River resulting in increased flood risk within the Des Moines River Basin. Following the 2008 Des Moines River flood, the District re-evaluated regulated flow frequencies on the Des Moines River. The Regulated Flow Frequency Study, completed in early 2010, concluded the frequency of flooding on the Des Moines River had increased and indicated major flood events, like 1993 and 2008, are more likely to occur than previously estimated.

The purpose of the study is to update the Des Moines River Basin Master Reservoir Regulation Manual to better meet mission objectives based on changes in flood frequencies, land use, and reservoir sedimentation. The recommended plan would result in a revised Des Moines River Basin Master Reservoir Regulation Manual, which includes the Saylorville Lake and Lake Red Rock Water Control Plans. The District drafted this feasibility report with an integrated environmental assessment to present a detailed account of the planning, regulatory and environmental considerations resulting in the Recommended Plan.

Links

Current Plans: Water Control Plans, including regulation tables, for both Red Rock and Saylorville lakes can be viewed in the PDFs provided below.

Public Input

Comments about the Des Moines River Basin Master Reservoir Regulation Manual Update may be directed to: CEMVR_Planning@usace.army.mil or (309) 794-5704. The review and comment period closes August 31, 2018.

Update Timeline

The Des Moines River Basin Master Regulation Manual revision process is underway. A draft copy of the Feasibility Report with Integrated Environmental Assessment is included below and the Rock Island District is accepting public feedback and comments. The public review period will close on August 31, 2018. The final Des Moines River Basin Master Regulation Manual Feasibility Report with Integrated Environmental Assessment will be released in fiscal year 2019.